Electrical distribution by alternating currents.



P. U. HEWITT. ELECTRICAL DISTRIBUTION BY ALTERNATING CURRBNTS.

' AP PLIOATION FILED MAR. 21, 1911.

L lfissago Patented Sept. 15, 1914 A TTOR/V E Y UNITED STATES PATENT oFFiloE.

PETER COOPER HEWITT, OF RINGWOOI) MANOR, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS, TO COOPER HEWITT ELECTRIC COMPANY, OF HOBOKEN, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELECTRICAL DISTRIBUTION BY ALTERNATING CURREN TS.

Specification of Letters Patent.

Patented Sept. 15, 1914.

Original application filed April 25, 1903, Serial No. 154,304. Divided and thisjapplication filed March 21,

To all whom it may concern Be it known that I, PETER CooPER HEWITT, a citizen of the United States, and resident of Ringwood Manor, county of Passaic, State of New Jersey, have invented certain new and useful Improvements in Electrical Distribution by Alternating Currents, of which the following is a specification.

It has been proposed to operate a direct current work circuit from a supply circuit fed by a source of alternating current by interposing at a suitable point or points in the system one or more devices permittmg the passage of current in one direction only. Under some conditions, the current thus delivered, though direct, tends to be intermittent to such a degree as to be objectionable. Such objectionable characteristics are noticgable, for example, when the like waves of a current derived from a single phase alternating source are delivered directly to the work circuit through devices of the character mentioned. above. If, in addition to the impulses thus directly supplied from the supply circuit to the work circuit, the latter could be impressed with supplemental impulses at times intermediate between direct impulses the flow of current would be steadier. In other Words if currents of different phase from that of the supply circuit can be delivered to the work circuit, the desired degree of steadiness would be more nearly attained- The current taken from the secondary of a transformer is nearly opposite in phase to that of the primary circuit, so that if provision be made to pass current directly from the supply circuit to the work circuit in the manner already proposed, and also from the secondary of a transformer fed by the supply circuit, the secondary current, like the primary, passing through a de vice or devices permitting current flow in only one direction, a much more nearly uni form supply of direct current will be operated'than without the use of the secondary current. In practice, the current from the secondary may pass through the same device as that from the primary. or it may pass through a separate device.

I have illustrated my invention in connection with a single phase alternating current supply circuit, although it is applicable Serial No. 615,913.

to polyphase circuits as well. In either case, theprimary and secondary impulses delivered to the workcircuit will be approximately symmetrical in the sense that the phase between successive waves or impulses delivered to the work circuit will be approximately the same.

The drawing is a diagram of one type ofcircuits embodying my invention an applied to the operation of a consumption circuit through Cooper Hewitt rectifiers.

In the drawing 1 and 2 are main conductors leading from any suitable source of single phase alternating currents and 14 and 15 represent vapor electric devices which may be rectifiers of the type now Well known. Taking the rectifier 14 as an example, it comprises a suitable container, a positive electrode, 8, and a negative electrode 7. Similarly the device 15 comprises a container with a positive electrode-9 and a negative electrode 7, the negative electrodes of the two devices being joined together outside the containing vessels and extending to one side of a work circuit 13, the other side of which passes by way of a wire, 4, through a reactance oI' inductance, 6, to the main conductor, 2. Between the mains 1 and 2 is connected a coil, 10, and a coil, 11, is con nected between the conductor 2 and a conductor, 20, leading to the positive electrode of the-device, 15. Such devices as 14 and 15 offer considerable resistance to the initial passage of current therethrough, but when this is overcome in a given direction, currents in that direction will flow with comparative ease, although they offer a practically prohibitive resistance to the flow of currents in the opposite direction under ordinary conditions of potential. It the conditions are such that the current falls to Zero between two succeeding waves, then means should be provided for overcoming the initial resistance at each zero point, but if means are provided for producing retardationoit the inductive efl'ect sufiicient to prevent the current from falling below the value required to prevent the initial resistance from reestablishing itself, then there will be a continuous flow when once thecurrent is started through the circuit. By using both the positive and the negative waves in a manner such as is herein described the full output of the generator may be availed of.

Any convenient well known means may be employed for overcoming the initial resistance in a given direction, and various other modes of connecting the circuits may be employed. When the inductive load of a work circuit is considerable, the inductive device, i, may be dispensed with.

It will be seen that the two devices, 14 and 15, are affected b two sets of impulses, one derived directly rom the supply mains 1 and 2 and the other indirectly through the transformer 10 and 11. As these impulses represent phases which are practically opposite each other, the time at which impulses of one phase are impressed upon the lamp will be substantially intermedlate between the times at which the other impulses are impressed upon it. This will tend to a comparative uniformity in the efiects produced in the two rectifiers and in the work circuit, 13. The device, 6, when it is used at all, will have the effect of retarding more or less these excessive current impulses and thus, as it were, smooth out the resulting current causing it to be more or less undulatory in character and preventing the occurrence of zero points.

I claim-as my invention- 1. In a system of electrical distribution, the combination with a single phase source and a direct current receiving circuit, of two vacuum rectifiers, each comprising an ex hausted container, and suitable electrodes therein, one of which is a vaporizable reconstructin cathode, connections from one termina of the suppl to an anode of one rectifier and connections from the other terminalof the supply to an anode in the other rectifier and connections for return currents from the cathodes to the supply through the work circuit, together with means for exciting the said cathodes.

,2. In a system of electrical distribution, the combination with a source of alternating current and a direct current work circuit, of a plurality of vapor rectifiers, each comprising an exhausted container with suitable electrodes therein, one being a vaporizable re-constructing cathode, means for connecting each supply terminal with a separate rectifier and means for returning rectified currents from the several cathodes through the work circuit to the source, in combination with exciting means for the several rectifiers.

3. In a system of electrical distribution, the combination with a. source of alternatin current and a direct current work circult, of a plurality of vapor rectifiers, each comprisin an exhausted container with suitable e ectrodes therein, one being a vaporizable re-constructing cathode, means for connecting each supply terminal with a separate rectifier and means for returning rectified currents from the several cathodes through the work circuit to the source, in

combination with exciting means for the several rectifiers and an inductance in series with the work circuit.

4. In a system of electrical distribution,

the combination with a source of alternating.

current supplied with terminals and an intermediate point and a direct current receiving circuit, of a plurality of vapor rectifiers, each comprising an exhausted container with suitable electrodes therefor, one of which is vaporizable and re-constructing, a connection for each of said rectifiers between a terminal of the supply and a terminal of the receiving circuit, the said work circuit being connected to th vaporizable electrode of each rectifier, and a connection from the other terminal of the receiving circuit to the intermediate point of the supply, in combination with exciting means for said rectifiers whereby said vaporizable electrodes are excited as cathodes.

5. In a system of electrical distribution the combination with a source of alternating current, an auto transformer, and a direct current receiving circuit, of a plurality of vapor rectifiers, each. comprising an exhausted container with suitable electrodes therefor, at least one of which is vaporizable and re-constructing, connections for each of said rectifiers between a terminal of the supply and a terminal of the receiving circuit, 'the said work circuit being connected to the vaporizable electrode of each rectifier and a connection from the other ters minal of the receiving circuit to an intermediate point of the auto-transformer in combination with exciting means for said rectifier whereby said vaporizable electrodes are excited as cathodesand an impedance traversed by current in the receiving circuit.

6. In a system of electrical distribution, in which alternating currents are rectified through vacuum rectifiers characterized by exhausted containers and va orizable re constructing cathodes, the met 0d of operation, which consists in rectifying each polarit of the supply current separately throug its own rectifier, assing current from the several polarities t rough a single work circuit and exciting each rectifier in such a direction that the several rectified currents flow in the same direction through the work circuit.

7. In an electrical distribution system, a work circuit, direct current translating devices therein, a supply circuit, carrying alternating currents, and connected directly to the terminals of the work circuit, in combination with a transformer'interposed between the supply and the work circuits, and

' the work circuit in one direction only.

York and State of New York this 15th day of March A. D. 1911.

PETER COOPER HEWITT. Witnesses:

WM. H. OAPEL, THos. H. BROWN.

suitable devices interposed at one or more points in the system whereby the impulses proceeding directly from the supply circuit, and the impulses proceeding from the sec- 5 ondary circuit are permitted to flow through Signed at New York in the county of New 

